Android has "Instant Upload" with the Google+ app. I'd like something similar for iPhone: an app that takes all my photos and uploads them to a private album on Picasa Web Albums. Jailbreak alternatives are fine too.

Searching the App Store for the word "picasa" gives me far too many results. There are some Picasa album-browsing apps, and a few uploading tools (mostly paid; free versions only upload thumbnails). Rather than testing out all 59+ apps myself, perhaps some fellow users here have personal experiences and recommendations?

I'm using Linux on my pc. This means that iTunes is not an option. (Yes, it's a hassle...) I am looking for something that can upload straight from iPhone to web, without requiring a computer as a middle step.

Bonus points for operation in the background, but I'll accept an app that requires to be foreground -- as long as it can upload.